Preschool teaching aid



FIG. 1 is an isometric view of a preschool teaching aid showing my new design;

FIG. 2 is a front elevational view thereof;

FIG. 3 is a rear elevational view thereof;

FIG. 4 is a top view thereof;

FIG. 5 is an enlarged right side elevational view thereof;

FIG. 6 is an enlarged left side elevational view thereof; and,

FIG. 7 is a bottom view thereof.

The broken lines depicting the key chains are for illustrative purposes only and form no part of the claimed design. 

The ornamental design for a preschool teaching aid, as shown and decribed. 